{"nrhp_refnum":"06000480","name":"Unit III, Dayton Project","other_names":["Bonebrake Theological Seminary","Union Biblical Seminary"],"category":"building","location":{"address":"1601 W. First St.","address_restricted":false,"city":"Dayton","county":"Montgomery County","state":"OH","lat":39.75698290500003,"lon":-84.22178137899994,"geom_source":"nps_gis"},"listed_date":"2006-06-07","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Science","Military"],"significance_levels":["state"],"summary":{"what_it_is":"A 1.38-acre site at 1601 West First Street in west Dayton, Ohio, where six surviving one-story concrete-block buildings built in 1944 for the Monsanto Company stand on the grounds of the former Bonebrake Theological Seminary. The site was used as Unit III of the Dayton Project.","why_significant":"The site is significant under Criterion A for its link to the 1942-1946 Manhattan Project and atomic weapons development, since Monsanto used it for polonium research and refinement. The six surviving buildings keep their quickly built wartime exterior character. The site also has religious history as the home of the United Brethren seminary, with ties to Bishop Milton Wright, father of the Wright brothers.","narrative":"At 1601 West First Street in west Dayton, six plain concrete-block buildings recall a secret chapter of World War II. The 1.38-acre site began as a United Brethren seminary, where an 1879 Romanesque building, designed by Luther Peters, trained ministers until 1923. The Dayton Board of Education later bought it and used it as a teacher training school and then for storage. In 1943 the Monsanto Company took over the property as Unit III of the Dayton Project, part of the Manhattan Project, where researchers refined polonium. Monsanto repaired the seminary building and in 1944 added one-story reinforced concrete-block buildings for laboratories, a machine shop, a laundry and decontamination facility, a boiler house, and offices. The property returned to the school board in 1948, and the seminary building was demolished after 1955. The surviving buildings, a guardhouse and a perimeter fence keep their hurried wartime look, and some interior features survive. The site was listed for its role in early atomic weapons research, and it also reflects the history of the seminary and Bishop Milton Wright.","period_of_significance":"1943-1948","architect_builder":"Luther Peters (architect of the 1879 seminary building, since demolished); Monsanto Company built the 1944 buildings","architectural_style":"No Style","criteria":["A"],"status_note":"Six contributing buildings and one non-contributing shed remained in 2005; the 1879 seminary building was razed after 1955. Current use is listed as education (warehouse).","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:52:07.661046-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_OH/06000480.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/06000480/518da6a668-800.webp","url_1600":"https://nationalhistoricalregister.com/media/06000480/518da6a668-1600.webp","licence":"Public domain","author":"Nyttend","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Dayton_Project,_Unit_III,_buildings_4-6.jpg\" rel=\"noopener\">Nyttend</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Dayton_Project,_Unit_III,_buildings_4-6.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71990615","wikipedia":null,"wikidata":"https://www.wikidata.org/wiki/Q138610280"},"indexable":true,"url":"https://nationalhistoricalregister.com/ohio/montgomery-county/unit-iii-dayton-project-06000480/"}